Looking old enough to be thinking about college, Percy Jackson (Logan Lerman) is still horsing around with centaurs and satyrs at Camp Half-Blood, where he has developed a rivalry with hyper-competitive Clarisse (Leven Rambin), clearly the heir to some of war god Ares' more combative qualities. The hokey camp is protected from outside threats by a magical tree that Zeus created from the corpse of his fallen daughter Thalia (Paloma Kwiatkowski) just outside its gates -- an all-too-typical example of putatively classic storytelling updated to look wrong-headedly contemporary onscreen, courtesy of TV-quality visual effects.
Jake Abel), the "lightning thief" Percy dealt with in the first movie.
The plot involves Luke's attempts to summon Kronos and use the angry Titan (who looks like a videogame version of "Legend's" Lord of Darkness) to destroy Olympus -- a scheme that mistakenly assumes that whoever resurrects Kronos can control him. One of the pic's rare moments of inspiration comes in detailing Kronos' backstory, presented in an impressive sequence in which Percy perceives a stained-glass window come to life (not in the freaky "Young Sherlock Holmes" sense, but as an elegant standalone animated interlude).
Otherwise, the overall vibe suggests "Xena: Warrior Princess" as a Nickelodeon special, as Freudenthal encourages the kind of clownish acting normally found on kiddie TV. Lerman seems especially awkward in this context, having proven himself capable of far more serious and convincing performances elsewhere (including last year's "The Perks of Being a Wallflower"), and already transitioning from his boyish looks to the face he'll have in his 30s. The movie positions him as a lost kid seeking answers about his identity and fate from an unseen father, but he doesn't appear nearly as young as his questions sound ("Ever felt that everything you've ever done is all just luck or something?" he asks a nearby lake, hoping Poseidon will answer).
Percy's already delicate self-esteem is thrown topsy-turvy with the arrival of Tyson ("Big Love's" Douglas Smith), son of Poseidon and a sea nymph, which makes this gangly new arrival to Camp Half-Blood his half-brother -- and a Cyclops to boot. Of all the sketchy special effects in the film, none is more off-putting than Tyson's lone eye, which he mercifully covers with sunglasses for long stretches. That makes at least one character who doesn't have to suffer through 3D conversions of visually mediocre movies. The pic has better luck updating various other mythical monsters, ranging from the fire-breathing Colchis Bull to fearsome sea creature Charybdis (which looks like the aquatic version of the Sarlacc pit).
Still, "Sea of Monsters" seems incapable of finding elegant ways to introduce these CG attractions into the story and instead comes across like a lazy bedtime story the narrator seems to be making up as he goes. It's enough to make Homer hang his head as the episodic film stumbles from one corny setup to the next, operating on two shaky assumptions: first, that audiences remember the basics of mythology, and second, that they'll find it clever when the film name-drops classic characters in silly new situations. (Circe's island becomes an amusement park, the eponymous "Sea of Monsters" is revealed to be the gods' name for the Bermuda Triangle, and so on.)
It's easy to forget this is a dead religion that novelist Rick Riordan and screenwriter Marc Guggenheim are mangling to fit the modern world, though their flip treatment of the underlying legends begs the question how audiences might react if they attempted the same CliffsNotes-style riff on characters from the Old Testament or the Quran. Whereas the tale might have demonstrated the immortal appeal of Greek mythology, it mostly just exploits the fact that its target audience is still being forced to memorize the gods' exploits in grammar school, serving up a quest that's modestly more entertaining than doing homework while completely missing the point about nearly everything it depicts.
© 2013 Variety Media, LLC, a subsidiary of Penske Business Media; Distributed by Tribune Content Agency, LLC